This Phase II SBIR Project will develop an inexpensive, easy-to-use Indoor/Outdoor Navigation System (IONS) to assist and guide people who are blind. The system will follow a stored map, using GPS for location outdoors and providing location indoors with an inertial guidance system that is periodically updated and re-centered through a small number of light fixtures which are modulated to give a location signal while still providing non-flickering illumination. IONS will provide a seamless transition from outdoors to indoors, allowing one system to be used for all wayfmding. Users can access maps through wireless networks (WiFi) and can use IONS to create their own maps for later use or for sharing with blind friends. Phase I demonstrated the concept and showed performance indoors equivalent to verbal directions given by a skilled mobility specialist. This project will develop a more convenient optical sensor for users, improve system accuracy and audio guidance, and incorporate a commonly used mapping database. The project will develop software for use on more powerful computers and ultimately for use on personal data assistants (PDAs) and even cellphones. In Phase II the system will be installed in a commercial facility and its full indoor/outdoor capability demonstrated and evaluated in comparison with verbal wayfinding techniques by having subjects follow a route outdoors to the door of a building, then indoors to reach a specific destination. This system will help people who are blind to live and travel more independently and increase their opportunities and capability for employment. It will enhance their lifestyles and decrease their dependence on sighted people. The system should also have value for people with cognitive disorders and those who are unable to read signs or who would otherwise benefit from audio guidance in wayfinding. Products resulting from this project will be the computerized IONS system for wayfinding, the remote Talking Lights optical sensor and software. [unreadable] [unreadable] [unreadable] [unreadable]